As a branch of information technology, information security is concerned with various issues, which are referred to in technical terminology as security objectives. In addition to availability and confidentiality, the integrity constitutes one of the typical security objectives. This is to be understood to mean the prevention of unauthorized modification of information in accordance with the internationally standardized Common Criteria for Information Technology Security Evaluation (CC). The additional security objective of authenticity describes the characteristics of authenticity, verifiability, and reliability of an object, in particular of a device.
The aforementioned objectives are of particular importance in the relatively new research field of cyber-physical systems (CPS). Those skilled in the art understand this general term to mean the combination of information technology-related or software-related components with mechanical or electronic parts which communicate via a data infrastructure such as the Internet. One design of cyber-physical systems results from the networking of embedded systems via wired or wireless communication networks, in particular so-called sensor networks.
In order to determine the originality of a component, PCT Application No. WO 2013 160032 A1 describes that a signature which is associated with the component is verified with the aid of a public key, at least one individual characteristic of the component being used for detecting the originality, without exclusive access to secret data being necessary. An up-to-date identifier, for example, a PUF value, is created as a function of at least one component-specific characteristic of the component. If the up-to-date created identifier corresponds to the verified signature, the originality of the component is deduced. In this case, the signature corresponds to a code word which is encrypted with the aid of a private key, for example, a private key of the manufacturer of the component.